The present invention relates generally to the field of medical catheters, and in particular, to ultrasonic imaging medical catheters.
In recent years, the use of ultrasound systems for medical diagnostics has continued to grow. Ultrasonic systems are used in a plethora of medical fields and in a wide ranging number of diagnostic areas. As the desire to use ultrasonic imaging systems has grown, so has the level of sophistication of those systems.
To assist physicians and staff in performing diagnostic and therapeutic procedures, a number of ultrasonic imaging systems have been designed for use with catheters. In general, these systems comprise a single transducer element, frequently made of piezoelectric material, attached to the distal portion of an imaging catheter. Depending upon the procedure to be performed, the imaging catheter is inserted into the patient and the transducer is positioned within the patient to image a desired region of the patient's anatomy.
Many single transducer imaging catheters rotate the transducer in the distal end of the catheter in order to receive an image of a desired region. To receive images from the transducer, a transmission line is connected to the transducer, run the length of the catheter and connected to electronics used for displaying the images. Since the transducer and transmission line are rotated at a high rate of speed, the imaging catheters need to provide a means to transfer the transducer signal from a moving transmission line to a stable platform in order for the attached imaging system to produce a useable image. In order to accomplish this connection, many systems use some combination of springs, contact wires, slip rings or commutators in order to make physical contact with the rotating transmission lines. While generally successful in allowing the transducer-produced image to be received by the imaging equipment, such contacts, slip rings and the like tend to introduce noise and other interference which can detrimentally affect the electrical signals. Such components also are subject to wear and possible breakage due to the frictional contact between a moving part and a stationary part.
It would be preferable, therefore, to provide a method for transferring electrical signals from the transducer to the imaging equipment in a manner which reduces the chance of signal distortion or interference. It also would be desirable to provide a reusable system that does not rely solely on physical connections to transmit a signal. It would be further desirable to allow signals from a plurality of transducers to be received by the same imaging equipment. It also would be desirable to provide such a system for use with an ultrasonic imaging catheter.